Transverse oscillations and stability of prominences in a magnetic field dip

¹ Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, CV4 7AL, UK
e-mail: D.Kolotkov@warwick.ac.uk
² School of Space Research, Kyung Hee University, Yongin, 446-701 Gyeonggi, Korea
³ Central Astronomical Observatory at Pulkovo of the Russian Academy of Sciences, 196140 St. Petersburg, Russia

Received: 12 March 2016
Accepted: 13 April 2016

Abstract

Aims. We developed an analytical model of the global transverse oscillations and mechanical stability of a quiescent prominence in the magnetised environment with a magnetic field dip that accounts for the mirror current effect.

Methods. The model is based on the interaction of line currents through the Lorentz force. Within this concept the prominence is treated as a straight current-carrying wire, and the magnetic dip is provided by two photospheric current sources.

Results. Properties of both vertical and horizontal oscillations are determined by the value of the prominence current, its density and height above the photosphere, and the parameters of the magnetic dip. The prominence can be stable in both horizontal and vertical directions simultaneously when the prominence current dominates in the system and its height is less than the half-distance between the photospheric sources.